Research On The Influence To Asphalt Pavements Crack Sealing Adhesion By Temperature And Humidity

Crack in asphalt pavement is one of the most common damage .After the crack of the road surface presents , the water will enter the surface structure layer and the roadbed along the crack, the road bearing capacity will decline because of the interactive effect between traffic load and the water, but it also leads to other more serious damages of the road, some of which are intuitive to distinguish, but more of them can not be detected, they occur in the roadway interior structure and will cause the potholes of the appearance, even roadbed damages finally. Therefore, it is very important to patch and deal with the crack promptly. The crack sealing is one primary type of asphalt pavement preventive maintenances, it is the important means of handling the bituminous pavement early damage, it can prevent water damage and forestall the further development of damages. The crack sealing can extend asphalt pavement life for several years and achieves good economic and social benefits.The road sealant may fail after period of time; the lack of adhesion between sealant materials and cracks is an important reason .Many factors affect the sealant materials' adhesion. Internal factors: aggregate chemical properties, surface area, pore size, material surface-active, acid value, viscosity and so on; External factors: the cracks wall loose, dust of cracks walls, water in the cracks, the road surface temperature and so on. This article mainly discusses the influence to the adhesion of the road sealing material by road surface temperature and humidity.This article makes improvements to the usual adhesion experiment, evaluates the adhesion influence by the road surface temperature and humidity through tensile experiment. Having referred to the massive literature material and to the related maintenance department's investigation, the experiment chooses two kinds of typical crack width and two kinds of sealing materials. This article divides the tensile experiment into four different phases: ordinary elastic deformation stage; yield stage; development of large deformation stage; end-stage destruction, the specimen is not destroyed on the peak power stage but destroyed in the later stage of deformation. The sealing material, the crack width, the temperature, the humidity has no tremendous influence to change the peak strength and the peak deformation. When the test sample in the water-involved situation is destroyed , the destructive tensile force and the destructive deformation obviously drop, when the test sample in the dry situation is destroyed, the destructive tensile force grows along with the change of the test sample's temperature .Hence, the influence of the humidity is bigger than the temperature to the adhesion.Along with the crack width becoming larger, peak strength becomes smaller and destructive deformation becomes bigger. It can be explained that the increased crack asphalt volume accommodated in crack moderates the tensile force along with the crack width becoming larger, sealant materials transform under the small tensile force from the elastic condition to the viscoelastic condition, sealing materials itself and tensile force between the material and the crack wall will become smaller. This experimental conclusion has preferable relativity with routed methods, square reservoirs and shallow reservoirs perform well, whose widths are larger.